Disposal of hazardous waste, such as waste generated by a nuclear power plant, requires special procedures and containers. An effective way to dispose of such materials involves the compaction of the hazardous waste with a compactor capable of compressing the materials without any discharge of dust or other lightweight portions of the materials into the atmosphere. Such a compactor and method of compaction is described in my U.S. Pat. No. 4,273,037, which is specifically incorporated herein by reference in its entirety as if reproduced in full.
Due to the large amounts of hazardous waste materials which need to be disposed of, it is desirable to compact this waste into as small a space as possible; this requires that high pressures be exerted upon the waste in order to compact it in sealed waste disposal containers. Generally, these containers must meet standards set forth in Title 49 of the Code of Federal Regulations and/or any other requirements imposed by the particular use or customer. However, these containers suffer from two problems; at high pressures, the walls of the waste containers tend to buckle outward or collapse, and expansion of compressed material inside of the containers tends to make it hard to seal or fill them to their optimal capacity.
The prior art attempted to solve these problems with special containers such as the one illustrated in FIGS. 1, 2 and 3. Prior art waste container 10 utilizes a plurality of parallel steel hold-down rods 12 to help compress and maintain compression upon waste compacted in the container. The prior art hold-down rods 12 comprise a main rod 14 with flanges 16 on both ends. Flanges 16 engage opposed locking devices 18 attached to the inside faces 20 of opposed container side walls 22. With particular reference to FIGS. 2 and 3, it can be seen that each of the locking devices 18 are formed from a left track 24 and a right track 26. Tracks 24 and 26 are mirror images of each other and comprise connecting strips 28 connected to the inside faces 20 of side walls 22, projecting strips 30 extending perpendicularly from connecting strips 28, and retaining strips 32 extending perpendicularly from connecting strips 28. Downward sloping tabs 34 are formed in each of retaining strips 32 by punching out holes 36. Tabs 34 ar bent towards inside faces 20 of side walls 22.
In use, main rods 14 are slidably engaged between tracks 24 and 26 while flanges 16 on main rod 14 are inserted between retaining strips 32 and inside faces 20. Flanges 16 are pressed against the tops 40 of downward sloping tabs 34. As hold-down rods 12 are guided down locking devices 18, flanges 16 press against tops 40 of tabs 34 to bend them towards inner walls 32a of retaining strips 32; ideally, tabs 34 rebound towards inside faces 20 of side walls 22 after the flanges 16 no longer press against them. Flanges 16 also strengthen side walls 22 of the container 10 by pressing against inner walls 32a of retaining strips 32.
The purpose of tabs 34 is to allow downward motion of the flanges 16 in locking devices 18, but to prevent upward motion of flanges 16. In order for tabs 34 to work correctly, they have to be resilient enough to bend downward in locking devices 18 when flanges 16 are pressed down against them, and they must be strong enough to maintain their angle of projection towards side walls 22 when upward pressure is exerted against them by flanges 16 so as to prevent upward motion of hold-down rods 12.
However, tabs 34 tend to break off when high compaction pressures are used; this allows hold-down rods 12 to move upward as compressed waste expands. Furthermore, the design of the locking devices 18 uses up the space between tracks 24 and 26 which could be used for compacted waste, and locking devices 18 do not sufficiently add to the strength of side walls 22.
There is thus a need for a waste disposal container with an integral hold-down mechanism which can withstand high compaction pressures without breaking, can contribute to the strength of the container walls, and which uses up a minimum of space. It is the solution to these and other problems to which the present invention is directed.